30. CRETACEOUS FORAMINIFERAL BIO-ISOTOPE STRATIGRAPHY OF HOLE 967E AND PALEOGENE PLANKTONIC FORAMINIFERAL BIOSTRATIGRAPHY OF HOLE 966F, EASTERN MEDITERRANEAN1Isabella Premoli Silva,2 Silvia Spezzaferri,3 and Antonio D’Angelantonio2 |
ABSTRACTDuring Ocean Drilling Program Leg 160, pelagic middle Eocene sediments were recovered from Hole 966F. Cretaceous and pelagic lower Oligocene sediments were recovered from Hole 967E. Both sites are located on the Eratosthenes Seamount, on the top and lower slope, respectively. The Cretaceous succession consists of pelagic sediments that overlie carbonate platform sediments. The deposition of carbonate platform sediments occurred in a shallow-water, lagoonal environment and ended in the late Aptian. Cretaceous pelagic sedimentation may have started in the Cenomanian(?) and continued up through the Maastrichtian. Despite poor recovery, a hiatus spanning the middle to late Helvetoglobotruncana helvetica Zone and the Marginotruncana sigali Zone is probably present in the Turonian, as inferred by the estimated very low sedimentation rates, and another hiatus is hypothesized between shallow-water carbonates and the overlying pelagic sequence, probably spanning the entire Albian and part of the Cenomanian. Another major hiatus was detected in Hole 967E where lower Oligocene sediments rest on upper Maastrichtian deposits. The planktonic assemblages reworked within the lower Oligocene sediments, however, indicate that sedimentation was originally more continuous on the seamount, and that several intervals were removed by downslope transport. Stable isotope stratigraphy (oxygen and carbon) tentatively allows comparison of the Cretaceous isotope record of Hole 967E with continuous and well-dated land sections in central Italy. |
|